Heterophyllin B enhances the benefits of intermittent fasting in the treatment of metabolic dysfunction‑associated steatotic liver disease via activation of GLP‑1R.

Intermittent fasting (IF) has shown particularly promising short‑term effects in improving metabolic dysfunction‑associated steatotic liver disease (MASLD), although its long‑term efficacy remains unclear. Heterophyllin B (HP‑B), a cyclopeptide compound derived from Pseudostellaria heterophylla, is known for its potent anti‑inflammatory and hypoglycemic properties. However, studies investigating the potential role of HP‑B in the management of MASLD are lacking. In vitro, an OA/PA‑induced lipid accumulation model was established using HepG2/Huh‑7 cells. The therapeutic effects of HP‑B and fasting‑mimicking conditions were evaluated through Cell Counting Kit‑8 assay, Oil Red O staining, reverse transcription‑quantitative PCR, and western blot analysis. For in vivo studies, C57BL/6J mice were fed a high‑fat diet and treated with HP‑B, IF, or their combination. Mechanistic validation was performed via adenovirus‑mediated GLP‑1R knockdown. The present study aimed to explore whether HP‑B can serve as an adjunctive supplement to enhance the benefits of IF in the treatment of MASLD. HepG2 and Huh‑7 liver cancer cells treated with oleic acid/palmitic acid (OA/PA) presented significant lipid accumulation, which was attenuated by HP‑B treatment and fasting. The combination treatment markedly reduced lipid levels and oxidative stress, as well as restored the mitochondrial membrane potential, with a synergistic effect over treatment alone. In addition, the combination of HP‑B and fasting upregulated glucagon‑like peptide‑1 receptor (GLP‑1R) and peroxisome proliferator‑activated receptor gamma coactivator 1‑alpha expression, reversing the OA/PA‑induced decline. In high‑fat diet‑fed mice, the combination treatment reduced hepatic lipid accumulation, decreased liver weight, decreased mouse body weight, and improved biochemical indices of liver function. The beneficial effects of HP‑B and fasting were reversed after silencing GLP‑1R with small interfering RNA or Ad‑GLP‑1R, emphasizing the critical role of GLP‑1R in mediating these protective effects. In conclusion, the synergistic effects of HP‑B and fasting on improving lipid metabolism and mitochondrial function are mediated primarily through the regulation of GLP‑1R, making it a promising therapeutic target for the treatment of MASLD and other lipid metabolism‑related disorders.